Arctic is getting wetter and stormier, scientists warn

As humans warm the planet, the Arctic region, once always frigid and frozen, is becoming wetter and stormier, with changes in its climate and seasons that are forcing local communities, wildlife and ecosystems to adapt. adapt, scientists said last Tuesday (13) in an annual assessment of the region.

Although 2022 was only the sixth warmest year on record in the Arctic, researchers this year have seen many new signs that the region is changing.

A September heat wave in Greenland, for example, caused the most severe melting of the island’s ice sheet at that time of year in more than four decades of continuous satellite monitoring. In 2021, a heat wave in August caused it to rain on top of the ice sheet for the first time.

“Perceptions about the circumpolar region are relevant to the debate about our planet’s warming, today more than ever,” said Richard Spinrad of the US National Oceanic and Atmospheric Administration (NOAA). “We are seeing the impacts of climate change happen first in the polar regions.”

Temperatures in the Arctic Circle have been rising much faster than the rest of the planet, transforming the region’s climate into something less defined by sea ice, snow and permafrost and more by open sea, rain and green landscapes.

Over the past four decades, the region has warmed at four times the global average rate, not two or three times as often reported, Finnish scientists said this year. Some parts of the Arctic are warming at up to seven times the global rate, they say.

Nearly 150 experts from 11 countries compiled this year’s assessment of Arctic conditions, the Arctic Report Card, which NOAA has produced since 2006. This year’s report was released Tuesday in Chicago at a conference of the American Geophysical Union, the society of earth, atmospheric and oceanic scientists.

Warming at the top of the Earth raises sea levels around the world, changes how heat and water circulate in the oceans, and could even influence extreme weather events like heat waves and storms, scientists say. But Arctic communities feel the impacts first.

“Our homes, livelihoods and physical security are threatened by rapid melting ice, warming permafrost, more heat, wildfires and other changes,” said Jackie Qatalina Schaeffer, author of a chapter in the bulletin on local communities, director of climate initiatives from the Alaska Native Tribal Health Consortium and an Inupiaq native from Kotzebue, Alaska.

Between October 2021 and September of this year, air temperatures above Arctic lands were the sixth highest since 1900, the report said, noting that the past seven years have been the warmest. Rising temperatures have helped plants, shrubs and grasses to grow in parts of the Arctic tundra, and 2022 has seen levels of green vegetation that were the fourth highest since 2000, particularly in the Canadian Arctic Archipelago, northern Quebec and central Siberia.

Three main factors may be increasing precipitation in different parts of the Arctic, said John Walsh, a scientist at the International Arctic Research Center at the University of Alaska in Fairbanks and also an author of the bulletin. First, warmer air can hold more moisture. Second, as sea ice retreats, storms can suck in more open ocean water.

Sea ice indicators have rebounded this year after near record lows in 2021, but were still below long-term averages, the assessment found. March is normally when the ice is at its greatest extent every year, and September is at its lowest. At both points this year, ice levels were among the lowest since satellites make reliable measurements.

The third factor is that storms are passing through warmer waters before reaching the Arctic, fueling them with more energy, Walsh said. Typhoon Merbok’s remnants traveled over unusually warm waters in the northern Pacific in September before slamming into communities along more than 1,000 miles of Alaska’s coast.

The Greenland ice sheet has thinned over the last 25 years, and 2022 was no different. But what caught the attention of scientists was an extraordinary increase in melting in September, the kind of event that would normally be seen in midsummer.

In early September, a high-pressure system brought in warm, humid air that sent temperatures in parts of Greenland up to 2.22°C above normal for that time of year. More than a third of the ice sheet has melted, according to the bulletin. Later that month, remnants of Hurricane Fiona swept across the island and caused more than 15% of the ice sheet to melt.